Primary-source AI tax research for Claude & ChatGPT
TaxMCP connects Claude and ChatGPT to the tax code, regulations, IRS guidance, and Tax Court, with links you can verify.
What are the requirements for the home office deduction?
Under §280A, a home office deduction requires the space to be used:
What about the simplified method?
Works inside the AI tools you already use
The Problem
General AI can produce confident tax answers without a source you can inspect. Standalone research platforms add another interface, another subscription, and another workflow. TaxMCP gives the assistant you already use a direct path to primary authority.
Connect TaxMCP, ask a real question, and check the results before rolling it out firm-wide.
ChatGPT and Claude can still get the analysis wrong. Reviewers get the actual section or ruling to check against.
TaxMCP searches public tax law. No client returns or documents needed, so your firm's data policy stays intact.
The Proof
We asked the same AI the same federal tax questions twice: once alone, once connected to TaxMCP. Every answer was graded against primary authority.1
on recent-law questions1
a failing 4.8 without TaxMCP
free of critical errors1
1 in 3 carried one without TaxMCP
exact figures & dates correct1
vs 89.6% without TaxMCP
overall accuracy grade1
up from 7.4 without TaxMCP
Right or tied on 93% of questions1.
Three real benchmark questions, graded 0–10. Average lift across the full set: +2.43.
EBIT or EBITDA basis for the interest limitation after OBBBA?
“EBIT basis. The EBITDA add-back only applied before 2022.”
“EBITDA basis, permanent. OBBBA §70303(a) struck the 2022 cutoff.”
What is the 2026 Form 1099 reporting threshold?
“$1,000 for 2026,” then “corrected” itself to the same wrong number.
“$2,000, raised by OBBBA §70433(a).”
What bonus depreciation rate applies to equipment acquired in mid-2025?
“40% bonus for 2025. Pending legislation could restore 100%.”
“100%, permanent. OBBBA §70301; Notice 2026-11.”
1 TaxMCP-run benchmark across a stratified set of U.S. federal tax questions (single run), each answered by the same model with and without TaxMCP and graded against primary authority. Mean grader score 0–10; ranges are standard error across questions. Read the methodology, definitions, and scope.
How It Works
Add TaxMCP to your AI assistant, then ask tax questions the way you normally would.
Add TaxMCP to Claude Desktop, ChatGPT, or any MCP client. It's one URL.
Ask tax questions in plain English. “What are the QBI deduction requirements?” “Show me §199A.” Your AI searches the actual IRC, regs, and rulings.
Every result includes the exact section number, source URL, and cross-references—details you can verify and share with clients.
Features
Pull the full text of any U.S. Tax Court opinion by citation or case name (49,000+ opinions back to 1942) and gauge how influential one is with a citation graph built from 500,000+ links between opinions.
Ask questions the way you think about them. “Can my client deduct home office expenses?” returns the exact IRC sections, regs, and rulings that answer it.
Every result names the section or authority and links to the source.
See how sections connect. When you look up §199A, instantly find every regulation, ruling, and related code section that references it, and everything it references.
The Code, Treasury Regs, IRS Publications, Notices, Revenue Rulings and Procedures, plus Tax Court opinions on Pro+. One search.
We check official government sources regularly and update the index when the law changes.
Who It's For
Research client positions faster with cited IRC sections, regs, and rulings, right inside your AI assistant.
Professional-grade tax research without the enterprise price tag. Free to start, scales with your practice.
Every answer links to authoritative government sources you can verify and cite in memos and opinions.
Pricing
Free for individual practitioners. Upgrade for unlimited federal research, or add Tax Court case law and state tax codes with Pro+.
Free
For individual CPAs, EAs, and tax professionals getting started with AI research.
Pro
Unlimited access to every federal tax source. For practitioners who need comprehensive research.
Pro+
For practices that need case law and multi-state coverage. Adds Tax Court opinions and state tax codes on top of everything in Pro.
State Coverage
State tax code research is included with Pro+. Iowa, Kentucky, Louisiana, Missouri, and Utah are the newest additions, with more coverage rolling out through 2026.
+ 16 more jurisdictions on the roadmap
Need a state that’s not listed? Let us know →Free Claude Skill
A free SKILL.md that turns Claude into a citation-grounded tax researcher – every answer tied to the IRC, Treasury Regs, IRS rulings, and Tax Court. Drop it into Claude Code or the Claude apps.
Get the SkillAsk it with and without TaxMCP, open the cited authority, and judge the result yourself.
FAQ
TaxMCP is a primary-source tax research connector for Claude, ChatGPT, and other MCP-compatible AI clients. It retrieves tax authority with links you can open and verify.
TaxMCP is built for CPAs, enrolled agents, tax attorneys, tax preparers, and accounting firms that want primary tax authority inside their existing AI workflow.
Open the source link in the result, review the cited section or authority, and confirm the effective date and version for your facts.
TaxMCP covers the Internal Revenue Code, Treasury Regulations, 29 IRS Publications, IRS Notices from 2003–present, and Revenue Rulings and Revenue Procedures from 2019–present. Pro+ adds 49,000+ U.S. Tax Court opinions dating to 1942 and state tax codes across supported jurisdictions.
TaxMCP retrieves public tax authority and does not require a client return or supporting documents. MCP tool arguments are not persisted by TaxMCP.
TaxMCP helps you find and inspect authority. Apply your professional judgment to the facts and verify the cited source before relying on it.
TaxMCP works with Claude Desktop and ChatGPT, plus other MCP-compatible clients.
Current Tax Answers
Concise tax answers with effective dates, limits, and links to the controlling government sources.
72.5¢ through June; 76¢ beginning July 1.
Up to a $25,000 deduction for qualified tips.
Up to $12,500, or $25,000 on a joint return.
Up to $10,000 for a qualifying new vehicle loan.
California does not conform to federal §168(k) bonus depreciation.
From the Blog
See how TaxMCP powers source-linked agentic AI tax research, what a safe research agent should do, and where CPA review and firm controls still matter.
Use TaxMCP with ChatGPT or Claude for source-linked AI tax research. A 2026 CPA workflow with prompts, verification steps, and primary-source citations.
A TaxMCP guide to AI tax research tools, with a source-first recommendation and a factual comparison of search, citations, coverage, and workflow fit.
A practical 15-minute workflow for turning a client message into a clear answer, a primary-source citation, and a reviewable file note.
An AI tax research assistant combines a conversational model with tax authority it can retrieve. Here is what it should show you before you rely on an answer.
OPR Alert 2026-19 applies existing Circular 230 duties to AI-assisted tax work. What it says about review, client data, and professional responsibility.